J a m e s a



J. A. LAWSON.

Ho-t -Air Furnace.

No. 70,445. Patented Nov. 5,1867.

IZM v firmin- 6 N- PETERS, PHOTOZUTHOGRAPHER, WASHKNGTON, B C.

JAMES A. LAWSON O-F TROY, NEW YGRK.

Letters Patent No. 70,445, dated November 5, 1867.

IMPROVEMENT IN HOT-AIR FURNACES.

digs firlgcbnlt nfrrrrt in in ilglSt hitter; and: mm mating part at the. time.

TO ALL WHOM IT MAY CONCERN:

Be it known that I, J, A. Lawson, of Troy, of Rensselaer county, in the State ofNcw York, have invented certain new and useful Improvements in Hot-Air Furnaccs, (adapted particularly for burning wood;) and I do hereby declare that the following is a full and exact description thereof, reference being had to,the accompanying drawings, making part of this application.

My invention relates tho-certain new and useful improvements in hot-air furnaces, and-has for its object a simple and economic form or construction of furnace, which shall at the same time afford the greatest possible cii'cetive radiating surface, and induce to the best expenditure of the heat generated by the consumption of a given amount of fuel; and to these ends my invention consists in the several characteristic features of construction hereinafter more fully described and claimed.

To enable those skilled in the art to make and use my invention, I willproceed to describe the construction and operation of a furnace embodying my improvements, referring by letters to the accompanying drawings, in which- Figure 1 is a side elevation of one of my improved furnaces.

Figure 2 is a vertical cross-section at the line rum, fig. 1.

Inthe several figures the same parts are designated by the same letters of reference.

A is the fire-chamber, b the grate, and C the ash-pit of the furnace, which parts maybe formed and arranged as shown, and are made about in the usual manner. The dome or roof of the fire-chamber, or that portion in which the products of combustion arise fromthe fire, is made'of a gothic form, as shown at f, and immediately over and on each side of this roof is arranged the series of radiators D D, &c., the peculiar form and arrangement together of which are clearly shown in the drawings. Each one of these radiators is of a diamond shape,

and communicates at its lower angle, at o, withone of two horizontal flues or pipes, EE, and each pair, or oppo site couple, of said radiators, may be made to communicate or connect, as seen at u, fig. 2. The two pipes or horizontal fiues E E extend the entire length of the furnace, and'arc connected or communicate near the middle of their length by a cross-pipe or flue, I, from which extends the smoke pipe G, through which the v smoke, gases, etc., are carried 05 in the usual manner. The gothic or peaked prtionfof the dome, it will be seen, does not start from the extreme sides or edges of the top of the fire-chamber, but a short distance therefrom, seas to leave a fiat portion'all along each side of the said portion), on which are supported the lower portions of the diamond-shaped radiators D, and through which are numerous openings, each forming a com munication between the interiors of the radiator and the fire-chamber, as shown at m m, fig. 2. The directions of the main currents of the product of combustion, as they risc from the fire-chamber, are indicated .by

thc'blue arrows in the drawings, from which it will be seen that the currents of heat from the fire asceud into the radiators on each side at m m, and thenvdividing pass upward in divergent lines to the middle of each radiator, where they begin to converge toward the points a, where they enter the horizontal flues E E. After entering these pipes or flues from each of the numerous radiators, the products of combustion have to pass along said fiues E from their ends to their centres, where they pass into the cross-pipe I, and thence immediately into the smoke pipe or exit-flue G. t It will be seen that by the peculiar form of radiators D the currents of ascending heat are first divided after entering at m, and caused to pass obliquely, and are then conveyed in oblique flues and united at a. By this method of forming the radiator it will be understood the heat in ascending has to take a circuitous course, and passing obliquely along the inner surface of the radiators D necessarily heats these surfaces highly, and the exterior oblique surfaces of said radiators are correspondingly affected in imparting their heat to a' large volume of cold air rising constantly in contact with said oblique surfaces. It will be understood that by having a series of radiators on each side, communicating at m, all along the entire length of the fire-chamber, as described, a very uniform draught, and complete and even consumption of the fuel'all over the grate or bed of the fire will be effected, while at the same time-the products of combustion will be carried ofi' from so many points of'thc fire-chamber, and distributed through so many channels, that about all the heat generated will have become absorbed and radiated by the radiators D andflues E before the currents will have reached the exit G, so that nothing but the smoke, gases, etc., will pass ofi' there, and

the heat will have been utilized to the greatest practical extent. The oblique or gothic form of the dome f I deem of importance and advantage, since thereby the roof of the fire-chamber is increasedin its superficial area, while, at the same time, currents of air are economically heated near the bottom of the radiators, and are deflected by it toward the central and hotter portions of' the heating apparatus. Ihe radiators D may be employed with great advantage, without being so constructed and arranged as to communicate at n, (each pair or couplet as described,) but I deem it expedient and advantageous to form these communications, as thereby the tendency of the currents of heat, as they ascend from the fire-chamber to become equalized and evenly heat all parts of the series of radiators, is increased.

Of course the precise forms and proportions of the several parts of the apparatus may be varied without departing from the gist of my invention, and a portion of the characteristic features of my invention may be employed alone without losing the substantial advantages of my improvements.

Having fully explained the several features of my invention, what I claim as new, and desire to secure by Letters Patent, is-' v v p 1. The radiators D, constructed and operating substantially as described, that is to say, in such manner as to receive the heat at their junction with the fire-chamber, divide the currents, and then converge or reunite them at the upper end of the said radiator. I i

2. I claim the employment of two sets or series of such radiators, arranged and operating substantially as described for the purposes set forth. 7

3. I claim the employment, in connection with the two sets of radiators, of two horizontal pipes or con duits, E E, communicating with the upper ends of said radiators, and with the exit pipe G, near their centres. substantially as described.

4. I claim the dome or roofof the fire-chamber, so constructed as to extend up between the sets of radi ators, substantially as and for the purposes described.'

In testimony whereofI have hereunto set my hand this day of 1867.

JAMES A. LAWSON.

Witnesses:

JAMES W. GREENE, Gso. EVAHS. 

